Structural Rehabilitation of Historic Building in KoreatownApr 19 2018 · 0 comments · Nishkian Chamberlain, Seismic ·0
Since its construction in 1928, the historically significant Chapman Court structure has withstood the test of time in the heart of the densely populated Wilshire Center in Los Angeles, CA. This building is a unique example of Spanish Colonial Revival architecture with intricate Churrigueresque detailing, by a prominent Los Angeles architectural firm during the 1920s; Morgan, Walls & Clements. The original use, a sample of how history repeats itself, was a mix of retail and live/work spaces with the retail spaces on the ground floor and the studios and residential spaces adjoining a central corridor on the upper floors.
The building consists of a the main 2-story structure, approximately 39 feet tall, offering intermediate first and second floor mezzanines and a 76 feet tower at the southeast corner. The total building floor area of approximately 30,000 square feet is rectangular in plan with an open-air courtyard and short one-story plus mezzanine wings projecting to the north. A partial basement of approximately 1,240 square feet is located near the middle of the footprint.
Now, with an adaptation to the existing building, the revitalized floor and roof plans have been carefully designed to preserve the historic context, while maintaining the structural integrity of the building. Balancing these two principles has created a unique set of challenges for which Nishkian Chamberlain has come up with a unique set of solutions. Working closely with the client and architect has allowed for a collaboration that meets the requirements of all parties involved.
Three new full height reinforced concrete shear walls were introduced, which utilize a deep foundation system comprised of concrete grade beams and cast-in-place piles. This retrofit strategy allows flexibility for the owner and future tenants since the existing interior wood partition walls are no longer relied upon as part of the lateral system. New lateral elements provide support of the existing mezzanines, consisting of wood shear walls and concrete grade beams. At the roof, existing skylights have been retrofitted with tie-rod bracing in order to preserve the natural light, while adding a critical diaphragm tie at the roof.
Challenges that were encountered during the foundation design included working around the existing foundations and ensuring the new and existing foundation system would interact in an acceptable manner. Valuable recommendations from and collaboration with the Geotechnical engineering team allowed Nishkian Chamberlain to creatively develop a cost-effective and feasible design solution.
Preservation of certain historical elements was given special consideration during the design and detailing of each aspect of the building retrofit. Such attention is critical from the early to the final stages of design to ensure the historic value of the structure remains.
If you have questions about the rehabilitation, adaptive reuse or seismic retrofit of your Historic building or general questions about our structural engineering services, we encourage you to contact us at 310-853-7180 or email: NCinfo@nishkian.com for an evaluation.